For even more impressive effects on body composition: aim for exercise forms which elicit a positive hormonal response. This means lifting really heavy things (strength training), or interval training. Such exercise increases levels of the sex hormone testosterone (primarily in men) as well as growth hormone. Not only do greater levels of these hormones increase your muscle mass, but they also decrease your visceral fat (belly fat) in the long term.
Skimp on fluids, and your body will release an antidiuretic hormone that leads to water retention that could affect the scale, Dr. Setlzer says. While this sneaky effect is one reason why the scale is a poor measure of body mass loss, you can outsmart it by drinking more—particularly if you fill your glass with water or non-calorie alternatives like unsweetened coffee and tea.
And beyond that, weight-loss efforts can take an emotional toll. “It can destroy your relationship with food. It can lead you to feel obsessed and frustrated,” Albers explains. For some people, quitting dieting is better and healthier than continuing to try to lose weight. And whatever a person’s weight-loss goal, the priority should be first and foremost on health. “Eating for health frees you up emotionally and is based on improving your body rather than rejecting your body,” she says.
This two-week program mandates the use of heavy compound exercises to start every weight workout. By keeping heavy training in your program, you’ll force your body to keep its natural production of growth hormone (GH). High GH, which peaks while you sleep, is a key player in the fat-burning process. Then, by targeting individual body parts with Tabata-style work, you’ll increase local blood flow to working muscles. On each Tabata exercise, start with a weight you can handle for 12–15 reps. As the work drags on, your rep counts will fade. Pause only when needed, and perform partial reps if necessary to keep going the entire 20 seconds.
"When we’re lacking in sleep, our body’s hormones get thrown off balance which can impact our hunger levels the next day. We all have two hormones that affect our appetite: ghrelin and leptin. When we don’t get enough sleep, our ghrelin levels (the hormone that makes us feel hungry) rise, and our leptin levels (the hormone that makes us feel full) drop. This means that when we’re awake, we tend to eat more but feel less satisfied. Try going to bed a little earlier than usual to avoid this imbalance and remember to remove any distractions that might prevent you from nodding off."